In any of a variety of applications, it is important for materials to be dispensed in correct type, in proper combination, in proper order, etc., to ensure that a proper result is achieved. As an example, and in the context of chemical storage and dispensing, it is often important for a chemical or a group of chemicals used in a particular process to be dispensed in regulated fashion. This can include assurances that a correct type of chemical is dispensed, that a desired combination of chemicals is dispensed, possibly in a particular order, that a particular chemical or combination of chemicals is not dispensed, or to ensure or protect against any of a number of possible variations associated with a particular chemical processing operation.
While similar problems are found in any of a number of applications, the improvements of the present invention are primarily directed to the loading of chemicals into a desired processing unit. In this context, it is common practice to introduce a chemical (or different chemicals) into the processing unit through an access port or door which is sized and configured to receive the container (e.g., a vessel or bottle) which holds the chemical to be dispensed. When it becomes appropriate to dispense a particular chemical (or chemicals), the container is introduced into the processing unit, through the door, for the discharge of its contents. In many instances, the container will be pressurized to facilitate in the discharge of its contents.Recognizing the need to carefully control such chemical dispensing, steps have been taken to develop systems for regulating the processes which are used to dispense such materials. Various types of labeling have been used to better inform the handler of such materials of the particular identity, use, and any contra-indications which may be pertinent to such materials. This can include any of a number of special markings or color coding for prompting or warning against a particular use or combination. However, irrespective of the labeling which is used, such markings remain subject to being misread, or other human error.
For this reason, attempts have been made to automate such regulation of the dispensing process to provide further assurances of a correct, and safe result. As an example, the bottles for containing the materials to be dispensed have been provided with special shapes and/or sizes for "keying" such vessels to the dispensing apparatus with which the materials they contain are to be used. This can include variations in the size and/or shape of the bottle itself, or more commonly, special sizing and/or shaping of the neck, spout, etc., associated with the bottle. By correspondingly sizing and/or shaping the inlet or port for accessing the processing unit, the dispensing of materials can be automatically limited to those materials which are contained in the corresponding vessel, achieving an appropriate level of assurance.
However, such keying requires the use of special vessels, and special ports for receiving such vessels, which can limit the overall use of such systems. This also fails to effectively accommodate applications which call for changing operating conditions or requirements, or combinations of processes, conditions or requirements which require careful control. As an example, let it be assumed that in a particular process, either of two different chemicals need to be introduced at a given point, but that introduction of the wrong chemical at the wrong time, or in the wrong order, will lead to a hazardous condition. Keying each of the vessels containing the two different chemicals to the intended (same) access port would provide no assurances that the chemicals are introduced at the correct time or in the desired order. The use of different keys, to ensure that the two different chemicals are correctly dispensed, would then prevent both of the vessels from being introduced through the same (keyed) port. Other systems attempted for similar purposes have in practice been found to be similarly limited.